This proposal is an application for an ADAMHA Research Scientist Development Award (Level I). A program of supervised training and research is proposed, through which the candidate will study neuroendocrine substrates of genetic and environmental sources of variance in homeostatic behavioral and physiological processes. Continued instruction in quantitative autoradiographic image analysis and extensive training in molecular biological methods will be provided by Advisors, and supplemented by workshops and courses. As part of the proposed training and research, the Candidate will investigate the relationship of brain aldosterone binding and brain angiotensinogen gene expression to control of a model motivated behavior (salt consumption) and a regulated physiological process (the circulation). Genetic influences on these processes will be studied through analysis of phenotypic variation in behavior, physiology and neuroendocrinology subsequent to selective inter-and intra-strain breeding of homozygous rats with well characterized behavioral and physiological phenotypes. Environmental influences on salt appetite, the circulation, brain aldosterone binding and angiotensinogen gene expression will be evaluated after sodium depletion challenges, or disruption of maternal behavior or sodium balance in the preweaning period. The mental health relevance of the proposed research derives from the insights that it will provide into genetic and environmental influences on homeostatic behavior and possible neuroendocrine mechanisms through which these influences are mediated. The training provided in the proposed work will provide the Candidate with important molecular neuroscience techniques that will have broad applicability in future psychobiological research.